Means for trimming grinding or analogous rotary bodies used in grinding or other machines



Oct. 25, 1960 M. J. KENT 2,957,471

MEANS FOR TRIMMING GRINDING 0R ANALOGOUS ROTARY BODIES USED IN GRINDING OR OTHER MACHINES Filed April 17, 1959 2 Sheets-Sheet 1 Oct. 25, 1960 M J KENT 2,957,471

MEANS FOR TRIMMING GRINDING 0R ANALOGOUS ROTARY BODIES USED IN GRINDING OR OTHER MACHINES Filed April 17, 1959 2 Sheets-Sheet 2 fl wd S ate Pa t MEANS FOR TRIMMING GRINDING R ANAL GOUS ROTARY BODIES USED IN GRINDING oR -"0THER M CHIN S a Maurice James Kent, Mitcham, England, assignor to Precision Grinding Limited, Mitcham Junction, England This invention has for its object to provide in a simple and convenient form a means for trimming grinding wheels or other analogous rotary bodies used in grinding or other machines.

A trimming means in accordance with the invention comprises a support adapted for attachment to the machine, a slide movable on the support in a direction at right angles to the spindle of the wheel or the like to be trimmed, a second slide mounted on the first slide and movable in a direction parallel with the said spindle, a hollow pivot post secured to the second slide, an angularly movable bracket of substantially arcuate, triangular or like form which at one end embraces the pivot post, a third slide attached to the underside of the other end of the bracket, an arm depending from the third slide and adapted to carry one or more trimming tools, and a microscope mounted on the upper end of the pivot post for locating the position and observing the movements of the trimming tool relatively to the wheel or the like to be trimmed.

In the accompanying drawings:

Figure 1 is a part sectional side elevation, Figure 2 a part sectional plan, and Figure 3 an end view of a trimming means embodying the invention.

Figure 4 illustrates the pattern of a graticule contained in the eye piece of the microscope.

Figure 5 illustrates one example of a grinding wheel having a shaped periphery which requires to be periodically trimmed.

Referring to the drawings, the trimming means there shown comprises a support 5 of any convenient form adapted to be attached to a grinding machine. On this support is mounted a slide 6 which is movable by a manually operable screw 7 in a direction at right angles to the axis of the spindle 8 of the grinding wheel 9, the screw 7 being operable by a knob 10. On the slide 6 is mounted a second slide 11 which is movable in a direction parallel with the said spindle, the slide 11 being operable by a screw 12 which is provided with a knob 13. On the slide 11 are formed a pair of extensions 14, arranged parallel with each other and spaced at a distance apart. Between these extensions is placed one end of a bracket 15 of arcuate, triangular or other like form, the bracket being attached to the slide 11 by a hollow cylindrical pivot post 16 inserted through the said extensions and bracket. At the underside of the other end of the bracket 15 is carried a third slide 17 which is movable by a pinion 18 acting on a rack 19, the pinion being operable by a knob 20. At the underside of the slide 17 is attached a sub-slide 21 in the form of a depending arm which at its lower end carries an adjustable holder 23 for a diamond or other trimming tool (or tools) 24, the sub-slide being movable by a knob 25 on a hollow and internally screwthreaded stem 26 which engages a screw 27.

On the upper end of the hollow pivot post 16 is mounted a microscope 28 of the prismatic or other convenient type whereby the operator can conveniently view the trimming tool through the pivot post. Also in the eye piece or otherwise within the microscope is contained a graticule (Figure 4) having thereon, for example a concentric arrangement of segmental arcs corresponding to the difierent curvatures which may be required to'be im-. parted to the periphery of the grinding wheel.

The first and second slides 6 and 11 serve to enable the tool 24 to be moved in linear paths relatively to the grinding wheel, so as to bring the tool into its working position relatively to the periphery of the grinding wheel.

The third slide 17 serves to impart to the trimming tool a movement in a straight line relatively to the grinding wheel. The sub-slide 21 serves to adjust the position of the trimming tool to a selected position determined by the graticule in the microscope, so that the bracket 15 can be moved in the desired paths relatively to the grinding wheel.

On the upper extension 14 of the slide 11 are provided two adjustable stops 29 (Figure 3) and on the bracket 15 is secured a stop 30 which is situated between the stops 29, the stops 29, 30 serving to limit the angular movement of the bracket. Also on the bracket are pivoted two locking pieces 31 which by engagement with a stop 32 on the slide 17 serves to hold the trimming tool in its central position relatively to the centre of the graticule.

When trimming a grinding wheel having a peripheral shape as in the example shown in Figure 5, the operator first makes the initial adjustment for bringing the tool into the desired position relatively to the grinding Wheel with the aid of the graticule in the microscope. After moving the locking pieces 31 to their inoperative positions, he then imparts an angular movement to the bracket 15 so as to bring the stop 30 into contact with one of the stops 29. By manipulation of the knob 20 he then causes the slide 17 to move the tool 24 trimming one of the flat faces of the periphery of the grinding wheel. When the stop 30 is moved into contact with the other stop 29, the operator by further actuation of the knob 20 causes the tool to trim the other flat surface of the grinding Wheel. To trim the curved portion of the periphery of the grinding wheel, the operator returns the locking pieces 31 to the operative position in engagement with the stop 32, and by direct manipulation of the bracket causes the tool to act on the curved portion of the Wheel periphery.

Whilst the invention is primarily required for trimming the shaped peripheral portion of a grinding wheel, it may be applied to other analogous uses. For example in some forms of machines in which cutting operations are performed on work pieces by electric spark erosion,

a rotary elect-rode is employed, and a trimming means as above described can be employed for periodically trimming the periphery of the electrode.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is:

1. Means for trimming a grinding wheel or an analogous rotary body carried by a spindle forming a part of a grinding or other machine in which the rotary body is used, comprising in combination a support adapted for attachment to the machine, a first slide carried by the support and movable relative thereto in a direction at right angles to the spindle carrying the rotary body to be trimmed, a second slide carried by the first slide and movable relative thereto in a direction parallel with the said spindle, a hollow pivot post secured to the second slide, a bracket connected to the second slide by the hollow pivot post and movable angularly about the latter, a third slide carried by and movable relative to the bracket, an arm depending from the third slide, means on the arm 3 for supporting a trimming tool, a microscope mounted on the upper end of the hollow pivot post for enabling the movements of the trimming tool relatively to the rotary body to be observed, and a graticule incorporated within the microscope, and having arcuate markings for determining the required initial position of the trimming tool relative to the rotary body.

2. Means according to claim 1, and having a subslide adjustably connecting the depending arm to the third slide.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain Sept. 22, 1938 

